Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely non-obvious context: the account is the user's own connected processor account rather than the platform's, the buyer pays that account directly, and the operation requires the projects:read scope. Only the return shape/pagination is left unspecified.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, front-loaded with the resource, followed by the disambiguating fact about who is paid and the permission scope. Nothing is wasted, though the opening fragment lacks a verb and reads slightly as a schema field description rather than an action.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With three all-optional params, no nested objects, and no output schema, the description covers what an agent needs: what data comes back, whose account it concerns, branch scoping, and the required permission scope. An explicit statement of return shape or empty-state behavior would close the remaining gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, with defaults for branch, project_id, and organization_id fully documented in the schema. The description's 'for this branch' hints at branch scoping but adds no syntax, default, or fallback behavior beyond what the schema already states, so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description identifies the specific resource set (products and prices on the user's own connected payment account, plus processor connection status) and scopes it to a branch. It lacks an explicit verb (list/read), but the noun-phrase framing plus the scope statement makes the returned data unambiguous, and no sibling overlaps this billing domain.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied rather than stated: an agent can infer it should call this to inspect the user's payment products/prices or verify a processor is connected. There is no explicit when-to-use, no exclusion, and no named alternative (there are no sibling billing tools to route against), so it stops at implied guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.